Integral sliding mode controller for trajectory tracking control of Stewart platform manipulator

In this paper, sliding mode controller (SMC) and integral sliding mode controller (ISMC) are designed for a variable speed wind turbine. The main objective of the controller is to optimize the energy captured from the wind at below rated power. To overcome the steady state error, the ISMC is introduced. However, in the presence of large uncertainties, ISMC control approach produces oscillatory phenomenon due to the higher needed gain. To eliminate the tradeoffs between the ISMC tracking performance and the high gain at the control input, we have introduced a new method based on the modification of the output tracking error through the use of the exponential function in order to eliminate the reaching phase. The stability of the proposed ISMC is analyzed by Lyapunov theory and the control action didn't show any chattering. The simulation results of ISMC are presented and the control performance is compared with conventional SMC.

In this paper, a proportional-integral sliding mode control (PISMC) method is presented to achieve the attitude and position control of an unmanned helicopter system for autonomous hovering. The PISMC includes the advantages of both conventional sliding mode control (SMC) and integral sliding mode control (ISMC). The proposed PISMC algorithm is capable of stabilized attitude and position control for unmanned helicopter autonomous hovering, and it offers a performance improvement over the conventional SMC and ISMC algorithms as well. The system performance is quantified and an experimental unmanned helicopter system is developed to access the performance of the PISMC. Both simulations and actual flight tests are conducted to verify the PISMC attitude and position control. The simulation results show that the PISMC tracking error is smaller and that PISMC converges faster than SMC does. The flight test results prove that the proposed PISMC is effective in the attitude and position control of unmanned helicopter autonomous hovering.

This paper proposes an integral sliding mode control with a novel model-based iterative feedforward compensating the hysteresis to finish high-precision positioning control of the piezoactuated stage. The Bouc-Wen model is established to design a novel iterative feedforward control (IFC) method. The IFC reduces the effects of inherent hysteresis on the positioning precision of the piezo-actuated stage. The positioning error of the IFC is inevitable because of the model uncertainty. Subsequently, an integral sliding mode control algorithm is implemented to further decrease the tracking error and enhance the anti-disturbance capability of the IFC. To reduce the chattering of the proposed controller, a boundary layer method based on Fal-function is designed. The stability of the integral sliding mode control is analyzed via Lyapunov stability theory. The feasibility of the proposed controller is certified by a series of simulation results. Compared with the IFC and conventional sliding mode control (CSMC) method, the proposed controller has higher performance in terms of the positioning precision of piezo-actuated stages.

In this paper, to improve the robustness and realize the precision positioning as well as speed control of the servo drive system, an integrated sliding-mode control (ISMC) optimized by differential evolution (DE-ISMC) algorithm is proposed. ISMC guarantees that a motor can reach at given position with given speed, and given speed is set first. ISMC, which is combined with speed regulator and position regulator, is different from the conventional sliding-mode control (SMC) replacing speed regulator. ISMC can guarantee that motor speed is controlled under position control mode, which is a novelty and an advantage of ISMC in this paper. To achieve good control performance of ISMC, parameters of it should be chosen exactly, so DE algorithm is selected to optimize them. The most significant influence factor of DE algorithm is the optimization iteration. Once parameters of ISMC are optimized under convergent iteration, servo system performance reaches given indices in the shortest time. Experimental results indicate that robustness of the servo system is improved; correctness and effectiveness of DE-ISMC are verified.

The integration of renewable energy sources (RESs) at the edge of the grid plays a contributory role in advancing the transition to a sustainable energy future. However, this transition introduces significant variability, which challenges the maintenance of frequency stability in power systems. To address the impacts of RES variability, various robust control strategies have been developed. This paper compares the performance of different advanced sliding mode control (SMC) approaches, i.e., super twisting (ST) algorithm‐based second order sliding mode control (STSOSMC), second order sliding mode control (SOSMC), double integral sliding mode control (DISMC) and integral sliding mode control (ISMC) with conventional sliding mode control (SMC) for load frequency control with stochastic RESs such as biogas generators (BG) and wind‐based doubly fed induction generators (DFIG). The impact of the advanced sliding mode controllers on the voltage and rotor angle stability of the system is also explored. The efficacy of the controllers is tested under different load disturbances, considering nonlinearities such as communication delay (CD), sensor inaccuracy (SI), governor dead band (GDB), and generation rate constraint (GRC). The results demonstrate that STSOSMC achieves superior frequency regulation with minimal chattering and outperforms other controllers in terms of settling time, overshooting, and undershooting in frequency deviation. The result also demonstrates the effectiveness of STSOSMC in managing the variability and disturbances of RESs. Therefore, it could be considered the most robust control mechanism from the edge of the grid system with high penetration of RESs.

The work presented here is concerned with the robust control problem for the inverted pendulum with mismatched disturbances via a non-linear disturbance observer (NDO)-based sliding mode control (SMC) method. The NDO-based SMC method provides a solution to the main limitation of conventional first-order sliding mode controllers that is the presence of high frequency oscillations in the control input known as chattering while retaining the nominal performance. To show the effectiveness of NDO-based SMC, both the conventional SMC and the integral SMC (I-SMC) methods are employed in the simulation studies for the purpose of comparison studies and results demonstrate the merits of NDO-based SMC.

In this study, a single sensor‐based maximum power point tracking (MPPT) algorithm is presented for permanent magnet synchronous generator‐based wind energy conversion system (WECS). The MPPT method used in this study uses only the wind speed sensor to generate the reference point required for the maximum power. A discrete‐time controller is proposed to bring the system to the reference point determined by the MPPT algorithm. The designed MPPT controller consisting of a new discrete‐time reaching‐law approach and a discrete‐time integral sliding mode control (SMC). The designed discrete‐time SMC‐based controller is implemented by using an Acorn RISC Machine (ARM)‐based LM4F120 microcontroller, and its performance is examined on a WECS emulator prepared in the laboratory. The results got from the real‐time studies prove that the proposed controller has the satisfactory performance to bring the system to the MPP. The performance of the proposed controller is also compared with the conventional sliding mode controller and perturb and observe method. The obtained results proved that the proposed controller has a better performance than the other controllers in terms of the settling time and output voltage's ripple.

To advance the efficiency and dynamic responsiveness of electric vehicles (EVs), this study introduces a comprehensive intelligent control and energy-management framework that couples a superconducting magnetic energy storage (SMES) assisted hybrid energy storage system (HESS) with a synchronous reluctance motor (SynRM) drive. The proposed configuration exploits the high power density and instantaneous response of SMES to enhance performance during transient load changes. To mitigate nonlinear behaviors, parameter deviations, and external disturbances within both HESS and SynRM subsystems, two resilient nonlinear controllers are designed: an Adaptive Barrier Function based Super-Twisting Sliding Mode Controller (ABC-STSMC) and a Synergetic Controller. The adaptive gains of the ABC-STSMC are tuned automatically through the Whale Optimization Algorithm (WOA) to ensure optimal robustness. Moreover, a deep reinforcement learning–driven energy management system (RL-EMS) governs real-time power allocation among the SMES, supercapacitor, and fuel cell, thereby maximizing overall efficiency and component longevity across variable driving conditions. The framework is validated through MATLAB/Simulink simulations and Hardware-in-the-Loop (HIL) experimentation. Quantitative comparisons with conventional Sliding Mode Control (SMC) and Integral Sliding Mode Control (ISMC) demonstrate that theWOA-optimized ABC-STSMC improves transient response by 28%, enhances tracking accuracy by 35%, and strengthens disturbance rejection. Simultaneously, the RL-EMS lowers switching losses and ensures balanced energy utilization. Collectively, the integrated control and management scheme offers higher reliability, robustness, and adaptability, positioning it as a promising solution for future high-performance electric mobility systems.

This paper investigated integral sliding mode controller (ISMC) to regulate the frequency of an islanded AC microgrid (MG) comprising distributed generators such as diesel engine generator (DEG), micro turbine(MT), fuel cell (FC), and energy storage system(ESS). The performance of MG has been closely examined under the action of fluctuated wind power and variable load perturbation. The results obtained with ISMC are compared with conventional sliding mode controller (SMC) and Linear Quadratic Regulator (LQR) controller. The effectiveness of the proposed ISMC is conformed against random wind power perturbation. The obtained results show the supremacy and reliability of the developed ISMC in stabilizing frequency deviation of the islanded MG.

This paper provides a comparative study of three Sliding Mode Control (SMC)-based fault tolerant controllers for trajectory tracking of a quadrotor UAV subject to actuator faults. Conventional SMC, Integral (ISMC) and Integral Terminal SMC (ITSMC) designs are designed and implemented to a quadrator UAV. The controllers' performance along with their respective robustness was assessed using various faulty conditions. Stability analysis was carried over using the Lyapunov approach. A thorough discussion of the controllers' respective performance in light of the obtained results was also performed and presented in the paper.

Adaptive integral sliding-mode finite-time control with integrated extended state observer for uncertain nonlinear systems

In order to weaken the influences of system uncertainties on the coordinated tracking control performance of the speed and tension system of the reversible cold strip rolling mill, a backstepping sliding model control strategy is proposed based on the extended state observers (ESOs). First, the ESOs are constructed to dynamically observe the system's unmatched uncertainties, which effectively improve the system's tracking control precision. Next, based on the backstepping control and the tracking differentiators (TDs), the integral sliding mode controllers (ISMCs) for the speed and tension system of the reversible cold strip rolling mill are designed, which solve the "differential explosion" problem of conventional backstepping control, and improve the robust stability of the system, Finally, simulation research is carried out on the speed and tension system of a 1422 mm reversible cold strip rolling mill by using actual data, and the results show the validity of the proposed control strategy.

This study firstly addresses an integral sliding mode control method for discrete time systems. The underlying continuous system is affected by both matched and unmatched uncertainties. The past value of the disturbance signal is taken as the estimate of its present value. The sliding mode controller is designed to ensure the existence of sliding mode in the presence of uncertainties. The proportional part is designed based on the analysis of closed-loop stability conditions. The controller design theory above is applied to an overhead crane system in later sections. The overhead crane system, which is a familiar control problem is described by a linear model, the parameters of which are estimated. It is affected by uncertainties such as friction, swing of the load and non-linearities because of changing rope length. Both simulation and experimental results are reported. The efficacy and robustness of the proposed controller are demonstrated.

Transportation electrification relies heavily on DC distribution networks powered by power electronics and the integration of various power electronic loads. These tightly regulated loads, known as constant power loads (CPLs), can destabilize the system when operating alongside source converters. This paper presents a novel hybrid controller to stabilize the DC bus voltage in the presence of CPLs in a DC‐DC boost converter (DDBC) within DC microgrids. To achieve this, the DDBC's dynamic model is first transformed into Brunovsky's canonical form through feedback linearization, resolving the non‐minimum phase issue and making the model more suitable for designing the proposed controller. Next, a robust control input is developed to ensure the convergence of all relevant states to their desired values while effectively managing disturbances and handling significant fluctuations in input voltage and load. The proposed controller combines a modified fast‐reaching law‐based nonsingular fast terminal integral sliding mode controller (FRL‐NFTISMC) with a backstepping controller (BSC) to address the negative incremental impedance behavior of CPLs, a common cause of grid instability. Furthermore, the composite controller guarantees large‐signal stability, verified through the Lyapunov stability theory. Finally, numerical simulations in MATLAB 2022b/Simulink demonstrate the controller's robustness under various conditions, outperforming existing nonsingular fast terminal sliding mode controller, conventional sliding mode controller, and proportional‐integral (PI) controllers. Experimental results from an in‐house hardware platform support the simulation findings and theoretical design, highlighting the controller's superior response speed and system resilience across different operating modes.

In real life, almost all systems are nonlinear in nature. The electromagnetic levitation system (EMLS) is one such system that has a wide range of applications due to its frictionless, fast, and affordable technique. Optimal control and sliding mode control (SMC) techniques are often used controllers for EMLS. However, these techniques can achieve the required levitation but lag in having perfect set-point tracking and robustness against uncertainties. To get over these drawbacks, this article proposes the design of unconstrained mismatched uncertainties, constrained mismatched uncertainties, and integral sliding mode control with mismatched uncertainties for the current-controlled-type electromagnetic levitation system (CC-EMLS). The modeled equations of CC-EMLS are transfomed in terms of the mismatched uncertainties, and the required control action is obtained with and without constraints on the control input. The quadratic performance function is suggested for the unconstrained control scheme and is solved using the Hamilton–Jacobi–Bellman (HJB) equation. The non-quadratic cost function is designed for the constrained control method, and the HJB equation is utilized to obtain the solution. Both control schemes provide robustness to the system, but deviations in the set point are observed in tracking the position of the ball when the changes in the payload occur in the system. Therefore, integral sliding mode control with robust–optimal (IOSMC) gain is proposed for the CC-EMLS to overcome the steady-state error in the other two schemes. The stability is proven using the direct method of Lyapunov stability. The essential studies based on the simulation are carried out to showcase the performance of the proposed control schemes. The integral performance indicators are compared for all three proposed control schemes to highlight the efficacy, robustness, and efficiency of the designed controllers.